On Unix systems,
Perl treats any relative paths in the PATH environment variable as tainted when starting a new process.
Previously,
it was allowing a backslash to escape a colon (unlike the OS),
consequently allowing relative paths to be considered safe if the PATH was set to something like /\:..
The check has been fixed to treat . as tainted in that example.

The list above is almost certainly incomplete as it is automatically generated from version control history.
In particular,
it does not include the names of the (very much appreciated) contributors who reported issues to the Perl bug tracker.

Many of the changes included in this version originated in the CPAN modules included in Perl's core.
We're grateful to the entire CPAN community for helping Perl to flourish.

For a more complete list of all of Perl's historical contributors,
please see the AUTHORS file in the Perl source distribution.

If you find what you think is a bug,
you might check the articles recently posted to the comp.lang.perl.misc newsgroup and the perl bug database at https://rt.perl.org/ .
There may also be information at http://www.perl.org/ ,
the Perl Home Page.

If you believe you have an unreported bug,
please run the perlbug program included with your release.
Be sure to trim your bug down to a tiny but sufficient test case.
Your bug report,
along with the output of perl -V,
will be sent off to perlbug@perl.org to be analysed by the Perl porting team.